Akermanite
Kusaka K, Hagiya K, Ohmasa M, Okano Y, Mukai M, Iishi K, Haga N
Physics and Chemistry of Minerals 28 (2001) 150-166
Determination of structures of Ca2CoSi2O7, Ca2MgSi2O7, and Ca2(Mg.55Fe.45)Si2O7
in incommensurate and normal phases and observation of diffuse streaks at high temperature
Sample: T = 413 K
Melilite group
_database_code_amcsd 0008521
7.8436 7.8436 5.0070 90 90 90 P-42_1m
atom      x     y     z Biso
Mg        0     0     0  .72
Ca   .33220 .1678 .5057 1.27
Si    .1399 .3601 .9337  .59
O1        0    .5  .820  1.5
O2    .1405 .3595 .2544 1.47
O3    .0820 .1867 .7860 1.46